Try running the command gnome-language-selector. If that doesn't work, make sure you have the package language-selector-gnome installed.
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Alvin RowAug 12 '13 at 4:01

@DoR I had to install that package, after that the "Language Support" icon appears again! I think the cause was the im-switch package. Can you post your comment as an answer so I can accept it? Thanks
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dusanAug 13 '13 at 0:34

I get same problem in Ubuntu 13.10 too. "Language support" disappeared right after installing ibus framework, I didn't even set input method system as "ibus". I tried "sudo apt-get install language-selector" and it's back again. But I've still no idea why it just disappears.

Install im-swtich was the problem for me. So this fix this problem. sudo apt-get purge im-switch && sudo apt-get install language-selector-gnome then login and logout and the language icon should reappear in the system settings.
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Larry BattleNov 26 '13 at 3:12